This invention relates to a connector in which a pair of connector housings are fitted together while their fitting operation is guided, and the two connectors are electrically connected together.
FIGS. 5 and 6 show one a related-art connector disclosed in, for example, Japanese Patent Publication No. 2002-198127A (see the descriptions in pages 3 and 4, and FIGS. 5 and 6).
The connector 50 comprises female and male connector housings 51 and 55 which can be fitted together. The female connector housing 51 includes a peripheral wall 52 of a substantially square tubular shape formed integrally with an equipment, and male terminals 54 project into the interior of the peripheral wall 52. A locking projection 53 is formed on and projects upwardly from an upper surface of the peripheral wall 52, and is disposed substantially at a widthwise-central portion of this upper surface. A locking arm 58 on the male connector housing 55 is retainingly engageable with the locking projection 53.
A pair of upwardly-projecting guide ribs 60 are formed on the peripheral wall 52, and are disposed at opposite sides of the locking projection 53, respectively, the guide ribs 60 extending in a forward-rearward direction (i.e., the fitting direction) over an entire length of the peripheral wall 52. Also, a pair of guide ribs 61 are formed respectively on opposite side surfaces of the peripheral wall 52.
The male connector housing 55 includes a terminal receiving portion 56 for receiving female terminals 59, and a tubular portion 57 integrally connected to this terminal receiving portion 56 in surrounding relation thereto. The peripheral wall 52 can be fitted into a space between the terminal receiving portion 56 and the tubular portion 57.
The locking arm 58 is formed on a widthwise-central portion of an upper portion of the tubular portion 57. A locking hole 58a is formed through the locking arm. 58 in a direction perpendicular to the fitting direction, and the locking projection 53 on the female connector housing 51 is retainingly engageable in the locking hole 58a.
Recessed portions 62, corresponding respectively to the guide ribs 60, are formed at opposite sides of the locking arm 58, respectively. As the two connector housings 51 and 55 are fitted together, the guide ribs 60 are inserted into the recessed portions 62, respectively. Protruded portions 64, each having a guide groove 63 therein, are formed at opposite side portions of the tubular portion 57, respectively. The pair of guide ribs 61, formed respectively on the opposite side surfaces of the peripheral wall 52, can be inserted into the guide grooves 63, respectively.
When the male connector housing 55 is fitted into the female connector housing 51, the peripheral wall 52 is inserted into the space between the tubular portion 57 and the terminal receiving portion 56, and the guide ribs 60 are inserted respectively into the recessed portions 62, and the guide ribs 61 are inserted respectively into the guide grooves 63, so that the fitting operation of the two connector housings 51 and 55 is carried out.
However, the above connector 50 has the following problems to be solved.
The fitting operation of the two connector housings 51 and 55 are carried out while the guide ribs 60 and 61, formed respectively at the four portions of the peripheral wall 52, are held in face-contact with the recessed portions 62 and guide groove portions 63 (which are formed at the tubular portion 57), respectively. Therefore, there is encountered a problem that the sliding resistance increases, so that the fitting operation can not be effected smoothly.
When the two connector housings 51 and 55 are fitted together, the sliding resistance due to the sliding contact between the male terminals 54 and the female terminals 59 is added to the sliding resistance due to the sliding contact between the guide ribs 60 and the recessed portions 62, and the sliding resistance due to the sliding contact between the guide ribs 61 and the guide groove portions 63. Therefore, the total sliding resistance becomes large. Particularly in the case of the multi-pole connector, the sliding resistance, produced by the terminals 54 and 59, becomes large, and the efficiency of the fitting operation is lowered. When the sliding resistance increases, so that the efficiency of the fitting operation is lowered, the automation of a connector-assembling line can not be achieved.
Therefore, in order to reduce the sliding resistance between each guide rib 60 and the corresponding recessed portion 62 and to reduce the sliding resistance between each guide rib 61 and the corresponding guide groove portion 63, it may be proposed to provide a clearance or gap between the sliding surfaces of each guide rib and the corresponding portion. However, when such clearances are provided, the two connector housings 51 and 55 shake relative to each other during the fitting operation, so that the guiding performance is adversely affected. As a result, in some cases, the male terminal 54 strikes against the female terminal 59, and a tab-like electrical contact portion of the male terminal 54 is bent, and a box-like electrical contact portion of the female terminal 59 is deformed.
In the case where the connector 50 is used in an engine room of an automobile, a household electrical appliance (in which vibrations occur) or others, external vibrations are transmitted to the connector 50, thereby inviting a problem that the two terminals 54 and 59 rub each other, and are subjected to the frictional wear or corrosion.